Ключевые слова: alternative, battery, biomass, biomass energy, black, bulb, car, dam, design, eco, ecology, electric, electricity, element, energy, filled, flat, friendly, fuel, general, geothermal, glyph, icon, isolated, logo, nature, nuclear, ocean, panel, plant, power, print, recycle, renewable, resource, sign, silhouette, solar, source, sun, symbol, turbine, water, wave, web, wind, windmill,